Question

An element with molar mass \(M\,kg\,mol^{-1}\) forms a face centred cubic unit cell with edge length 405 pm. If the density is \(2.7\times10^{3}\,kg\,m^{-3}\). What is its molar mass \(M\)? \((N_A=6.0\times10^{23}\,mol^{-1})\)

• A. \(2.59\times10^{-1}\)
• B. \(2.49\times10^{-2}\)
• C. \(2.69\times10^{-2}\)
• D. \(2.89\times10^{-1}\)

Hint:

For FCC crystals always use \(Z=4\). For BCC, \(Z=2\) and for simple cubic, \(Z=1\).

Answer 1

The Correct Option is C